x86 Baker's read barrier fast path implementation.
Introduce an x86 fast path implementation in Optimizing for
Baker's read barriers (for both heap reference loads and GC
root loads). The marking phase of the read barrier is
performed by a slow path, invoking a new runtime entry point
(artReadBarrierMark).
Other read barrier algorithms continue to use the original
slow path based implementation, which has been renamed as
GenerateReadBarrierSlow/GenerateReadBarrierForRootSlow.
Bug: 12687968
Change-Id: Ie610c4befc19ff22378a8cba38b422dcacb54320
diff --git a/runtime/arch/x86/quick_entrypoints_x86.S b/runtime/arch/x86/quick_entrypoints_x86.S
index 463c9cf..da30331 100644
--- a/runtime/arch/x86/quick_entrypoints_x86.S
+++ b/runtime/arch/x86/quick_entrypoints_x86.S
@@ -1686,6 +1686,14 @@
UNREACHABLE
END_FUNCTION art_nested_signal_return
+DEFINE_FUNCTION art_quick_read_barrier_mark
+ PUSH eax // pass arg1 - obj
+ call SYMBOL(artReadBarrierMark) // artReadBarrierMark(obj)
+ addl LITERAL(4), %esp // pop argument
+ CFI_ADJUST_CFA_OFFSET(-4)
+ ret
+END_FUNCTION art_quick_read_barrier_mark
+
DEFINE_FUNCTION art_quick_read_barrier_slow
PUSH edx // pass arg3 - offset
PUSH ecx // pass arg2 - obj